I wanted to use DirecTV at a secondary home which didn't have a DirecTV dish. I had an old Dish Network dish, but it wouldn't work because the LNB was incompatible. I purchased this LNB to convert the Dish Network dish to DirecTV. FYI, I bought it from Amazon.com, and it was only $20, which was a bargain price.

I can confirm that it does work with DirecTV, but I don't know about any other satellite providers. The coax cables were already installed, so I essentially had to attach the LNB and re-point the dish to get DirecTV signal.

I used this on a 18" dish, and it was fully compatible, without having to replace any additional parts. I attached the coax cable as shown in the photo before mounting the LNB to the dish. I only use it with one receiver, but you can use it with two. The coax plugs do have rubber rings which is a huge plus. It's an awesome addition because the prevent water from seeping in, which eventually causes corrosion. The outer end of the coax also has a metal casing which fends off water. I replaced a Dish Network LNB once because of corrosion, but this shouldn't happen again. FYI, I also used an 11m wrench to tighten and secure the coax cables.

The next thing I did was mount the LNB onto the dish. I did have to wiggle it into place because there was a bit of resistance. As shown in the photo you only have to add one screw to mount it. The disappointing thing is that the screw from my old LNB was too big for this RCA LNB, so I went back and installed the screw afterwards. Surprisingly it held securely without putting the screw in.

A pointer is not necessary to point the dish, and I didn't use one, but it took some time to get a sufficient signal. I had to unloose these two screws in the photo to move the dish to set the elevation and azimuth for my location. There are several ways to do this, but I got the elevation and azimuth for my zip code from DirecTV.com. I used the pointer tool there. The top screw is for azimuth, and the bottom one is for elevation. You shouldn't immediately re-tighten the screws without checking the signal on your TV. I had to make a few minor adjustments to get the max signal, so you shouldn't depend entirely on the elevation and azimuth.
Once I received the DirecTV signal, it worked without issue. It's awesome because there is very little interference. It rarely drops signal, and I'm in an area with several trees so this has been an issue in the past. My receiver tends to show a signal of 90-100 at most times.

If you're in the market for a replacement LNB, I would definitely recommend it! It was one of the cheaper LNBs but it works, so I have no complaints!